Year	Number
2004-01-01	0.2502
2005-01-01	0.2462
2006-01-01	0.2569
2007-01-01	0.2892
2008-01-01	0.3309
2009-01-01	0.3578
2010-01-01	0.3820
2011-01-01	0.4103
2012-01-01	0.4479
2013-01-01	0.4896
2014-01-01	0.5354
2015-01-01	0.5515
2016-01-01	0.5731